The design of umbrella is not only limited to block out rain, but also can be used to block out sun light radiation. Normally, the umbrella is used during daytime to either block out the sun light radiation during sunny weather condition or block out rain during raining weather condition. During nighttime, the umbrella is only used to block out rain during raining weather condition. During raining weather condition, the visibility is very poor, especially during heavy down pouring. The problem with low visibility is magnify at nighttime when the degree of brightness is much lower than daytime.
For those who need to travel on the street during nighttime raining condition, not only do they have to battle with cold and wet weather, but also the road is full of hazardous condition. It is extremely difficult for a driver in a vehicle to see the pedestrian walking across the street under raining weather condition during nighttime. This is especially true for umbrella which has dark color. Even if the umbrella is in shining color such as yellow or bright red, during nighttime raining condition, the vision of the driver is still relatively low in compare to daytime sunny weather condition. Although most drivers are much more cautious under such hazardous condition, but accidents happened during nighttime raining weather condition are still at an alarming rate.